Thomas Reid on "First Principles" (Part Two)

Part One: Who Was Thomas Reid?

Reid on "First Principles"

       
The great conundrum faced by philosophers since time immemorial is the question “how do we know what we know?”  This question falls under the sub-category of philosophy known as epistemology.  Those who contend that all human knowledge arises through our senses are called “empiricists.”  Those who believe that our knowledge is grounded in our ideas (i.e. our mental powers and state of mind) are often identified as “idealists.”  

Enter the much better known contemporary of Reid, the German philosopher Immanuel Kant (1722-1804), whose volume Critique of Pure Reason, was first published in 1781.  What made Kant’s philosophy so important and ground-breaking was that Kant made a compelling case that while all knowledge begins with sense perception–the data received via our senses–the knowing process does not end there.  Without the mind having the innate ability to act upon these sensations so as to transform them into knowledge, the world would remain unintelligible to us despite the data coming from our senses.  Kant believed that there are specific mental categories which owe nothing to experience, and which are hard-wired into us which shape those sensations we do receive.  

These so-called a priori categories (i.e., they are in place before we experience the world) include notions of time and space, logic, and mathematics.  A creature without such categories would have the same sensations and see the same appearances we do, but would have an entirely different experience of them.  My dog and I see the same tree.  Since he does not have the mental categories I have, we experience the same tree quite differently.  According to Kant, we see not “the thing in itself,” but only the thing as interpreted by our minds according to the a priori categories.  This is reflected in Kant’s well-known distinction between the noumenal (the world beyond experience but which can reasonably be inferred from experience) and the phenomenal (the world which is actually experienced and accessed through the senses).

Reid, it has been said, worked backward from Hume’s skepticism to ask, “what would be necessary” if we are to know the world as it is?  Reid wonders “what capacities must the human mind possess in order to truly know the external world?”  He classifies these capacities as “first principles” which he believes are grounded in the so-called “common sense” of humanity.  These principles are simply assumed and cannot be proven.  We utilize them without any prior reflection upon them, nor can we “prove” them, because to do so we must utilize the very capabilities we are trying to prove.  Although people universally reason from these first principles even if they do not believe in God, whenever we seek to get behind “common sense” to discover why things are the way they are, Reid argues there is no way to explain the existence of these first principles and the common sense of humanity apart from God who created the world and has designed us to live and act within that world.  Reid writes,

I thank the Author of my being, who bestowed it upon me before the eyes of my reason were opened, and still bestows it upon me, to be my guide where reason leaves me in the dark.  And now I yield to the direction of my senses, not from instinct only, but from confidence and trust in a faithful and beneficent Monitor, grounded upon the experience of his paternal care and goodness.  In all this, I deal with the Author of my being, no otherwise than I thought it reasonable to deal with my parents and tutors.  I believed by instinct whatever they told me, long before I had the idea of a lie, or thought of the possibility of their deceiving me (Reid, Inquiry, in Works of, I.184).

The theistic implications of Reid’s first principles ought not be overlooked.  We reason via common sense because our Creator has designed us to do so.

Immanuel KantSince Kant too was awakened through his interactions with Hume, we should not be surprised that both Reid and Kant were chasing the same goal.  Reid wanted to challenge Hume’s skepticism, as did Kant–albeit Kant’s method of doing so was quite different than Reid’s.  Reid appealed to those things assumed by all humans in all ages and across all cultures–identifying those first principles which ground human knowledge in the real world–and in not mere experience or in mental categories.  This makes Reid a “common sense realist”–we do indeed apprehend the world as it is through ordinary daily activity.  Reid really ought not be classified as a pure empiricist, although he does fit within the empiricist camp.  Kant, on the other hand, thought the best way to do this was to define the limits of human reason by identifying those a priori mental categories which transform mere appearances of things into our knowledge of them.  Kant’s so-called “transcendental idealism” sets out the premise that knowledge begins when we receive appearances of external things via sense perception, but we cannot regard these appearances as objects of knowledge until our minds organize these appearances through a set of fixed a priori categories already present in the mind.

The critical issue with which Reid and Kant were wrestling is that we all have to start the knowing process somewhere.  But where, exactly?  We must assume certain things to be true and already in place in our minds from our earliest years of self-consciousness and prior to experience of the world, otherwise our sensations would remain just that–mere sensations and never pass into knowledge.  

Reid identified two types of first principles–necessary (certain) and contingent (probable) which provide the a priori framework to necessary understand the external world (Reid, Intellectual Powers, in Works of, 1:435).  Those first principles Reid identified as “necessary” (i.e., it is impossible to deny them) include logic (i.e., the law of non-contradiction) certain rules of grammar, mathematics, morals (unjust actions cause harm) and metaphysical realities–what we perceive actually exists.  Reid is certain that God would never allow an evil demon to deceive us as Descartes once wondered.  Reid also believed that whatever exists has a cause–in direct opposition to Hume’s skepticism about accepting things as “true” which he could not actually observe.
    
Those first principles which Reid identified as “contingent” include things such as consciousness of our own person (self-awareness), knowledge of the external world, that what I remember really did happen, that my personal identity truly exists as far back as I can remember, and that those things which I see and perceive really do exist.  Reid also argued that we have power as human agents to determine our own actions (we learn about causality, through our own agentic powers, as when infants, we strike the mobile above our heads which causes it to move), that we are able to tell truth from error, we know that other minds exist, and that human testimony is ordinarily true unless we have good reasons to believe otherwise.  Reid added that the future course of the world will be similar to what it has been in the past.

Reid was clear as to the importance he placed upon such first principles.

All reasoning must be from first principles, and for first principles no other reason can be given but this, that, by the constitution of our nature, we are under a necessity of assenting to them.  Such principles are part of our constitution, no less than the power of thinking:  reason can neither make nor destroy them; nor can it do anything without them. . . . A mathematician cannot prove the truth of his axioms, nor can he prove anything unless he takes them for granted.  We cannot prove the existence of our minds, nor even of our thoughts and sensations.  A historian, or a witness, can prove nothing unless it be taken for granted that the memory and senses may be trusted (Reid, Inquiry, in Works of, 1:130).

To deny these principles, Reid thinks, is absurd.

We must start the knowing process by assuming certain capacities are in place whether we can prove this or not.  Reid begins with first principles, both necessary and contingent.  Kant, on the other hand, rejects Reid’s realism, instead contending that we cannot see things as they really are, only our perceptions of them mediated through his famous “categories.”

Part Three